<?xml version="1.0" encoding="iso-8859-1" ?>  
<?xml-stylesheet type="text/xsl" href="pmathml.xsl"?>  
<html xmlns="http://www.w3.org/1999/xhtml" >  
  <head>  
    <title>mathml example</title>  
  </head>  
<body>  
<math xmlns="http://www.w3.org/1998/Math/MathML"  
      display="block">  
  <msubsup>  
     <mo mathsize="big">&#x2211;</mo>  
     <mrow>  
        <mi>k</mi>  
        <mo>=</mo>  
        <mn>0</mn>  
     </mrow>  
     <mi>n</mi>  
  </msubsup>  
  <mfenced separators="" open="(" close=")">  
     <mfrac linethickness="0">  
        <mi>n</mi>  
        <mi>k</mi>  
     </mfrac>  
  </mfenced>  
  <mo>+</mo>  
  <mfenced separators="" open="{"  close="" >  
     <mtable align="axis" equalrows="false"  
                          equalcolumns="false">  
        <mtr>  
           <mtd columnalign="left">  
              <mi>x</mi>  
           </mtd>  
           <mtd columnalign="left">  
              <mtext >if&#x00A0;</mtext>  
              <mi>x</mi> <mo>&#x003E;</mo> <mn>0</mn>  
           </mtd>  
       </mtr>  
       <mtr>  
           <mtd columnalign="left">  
              <mi>y</mi>  
           </mtd>  
           <mtd columnalign="left">  
               <mtext>otherwise</mtext>  
           </mtd>  
       </mtr>  
     </mtable>                                                                    </mfenced>  
</math>  
</body>  
</html>